The Urban Dictionary T-Shirt

a spin off term derived from "metric assload". someone heard a person say "metric assload" thought it was a cool phrase forgot the phrase then tried to use the phrase but didn't know it so they came up with metric shitload.
It is unclear whether the Metric Load or Fukton scale scale of measurement came first so both are acceptable in most countries.

dude, it's not a metric shitload...it's clearly a metric assload...i mean you see how it's spilling over right there...yea into that hole right there...anyway that part clearly makes it an assload.